1972 c10 ignition switch problem..?

[I_Wanna_Go_Fast]

Hey guys
Looking for a little help from the wealth of knowledge on this forum..
I have a 1972 c10 that I've built far from stock.
IT was originally built to haul my dads track car to and from the track. I now have it and have turned it into a street/strip truck.
built 489 bbc, th400 with manual valve body and a bunch of other goodies.

A problem surfaced towards the end of last year during a drag and drive I was competing in.

If I start the truck when cold, let it run for a bit and shut it off, everything is fine. If I drive it a while (an hour or more), when I go to shut it off it will act as if the ignition cuts off for just a second and then stays running. Its definitely not dieseling as others have experienced on here.
If I grab the end of the key and jiggle it around and try to point the tip of the key towards the floor, it will shut off.
I'm leaning towards a wore out ignition switch but wanted to check in here and see if there were any other possibilities.

I cleaned up most of the wiring on the truck - didn;t cut any wires - just removed the unneeded stuff like the emissions, etc.
There is no vacuum stuff on the truck and no HEI or anything like that.

Any help is greatly appreciated.
Thanks!